. >> at first glance, new york's barnard college looks pretty typical for a small school in a big city. located in upper manhattan, the campus is compact, covering just a few city blocks. about 2,400 students come here from all over the world, so therelots of diversity. but all barnard students have one particular thing in common -- they're all women. barnard is what's called a single-sex college. >> there are probably about 60 or 70 all-women's colleges out there in the united states now. and i do think it is very much about really building both women's self-esteem, their confidence levels. >> before you say "no way! not me," keep in mind that single-sex colleges often have close relationships with other schools. in barnard's case, the other school is right across the street -- columbia university. >> there are columbia students taking courses at barnard and barnard students taking courses at columbia. >> back in 1889, when barnard was founded, women were not allowed to attend columbia. they weren't allowed to vote, either. nowadays, most schools are co-ed, meaning they accept both ma